Issue #2045931 by PerthSam152, LinL, adsw12, joelpittet: Replace all module_exists() deprecated function calls.

This reverts commit cc84f390 - bad
commit message.

Issue #1987816 by pdrake, disasm, ParisLiakos, pguillard, vijaycs85, dawehner: Convert system_batch_page() to a new style controller.

Issue #2038135 by RobLoach, donquixote, Crell, ParisLiakos, catch: Use the Composer autoloader to make everything simpler.

Issue #2045923 by drupalrv, tim.plunkett: Replace all module_invoke_all() deprecated function calls in procedural code.

Issue #2017769 by pplantinga, clemens.tolboom, elachlan, katbailey, longwave: Fixed Links from update_helpful_links() should point to site root and not to update.php.

Issue #1890878 by corvus_ch, ygerasimov, berenddeboer, Crell, fubhy the cat, effulgentsia: Add modular authentication system, including Http Basic; deprecate global .

Issue #1988508 by katbailey: Stop pretending we support Symfony bundles when we really just have service providers.

Issue #1668866 by ParisLiakos, aspilicious, tim.plunkett, pdrake, g.oechsler, dawehner, Berdir, corvus_ch, damiankloip, disasm, marcingy, neclimdul: Replace drupal_goto() with RedirectResponse.

Issue #1984766 by sdboyer, Niklas Fiekas, msonnabaum: Fixed Start relying on Request/Response objects for cache handling.

Issue #1957154 by joates, ayelet_Cr, xjm | Berdir: Replace calls to drupal_container()->get('module_handler()') service with Drupal::moduleHandler().

This reverts commit c4e52bb6.

Issue #1827448 by RobLoach, sun, jbrown, tstoeckler: Use __DIR__ instead of DRUPAL_ROOT where possible/sensible.

Issue #1547008 by Berdir, Sutharsan: Replace Update's cache system with the (expirable) key value store.

Issue #1929656 by dawehner: Fixed ModuleHandler::setModuleList() should call resetImplementations() in order to avoid edge cases.

Issue #1331486 by katbailey, chx, sun, beejeebus, amateescu: Move module_invoke_*() and friends to an Extensions class.

Revert "Issue #1331486 by katbailey, chx, sun, beejeebus, amateescu: Move module_invoke_*() and friends to an Extensions class. Broke core tests after commit."

This reverts commit c80c3e18.

Issue #1331486 by katbailey, chx, sun, beejeebus, amateescu: Move module_invoke_*() and friends to an Extensions class.

Issue #1833516 by Berdir, chx, catch, webchick: Add $settings for low-level configuration - move things out of .

Revert "Revert the revert of Issue #1849004 by chx, xjm: One Service Container To Rule Them All. It was innocent after all."

This reverts commit a1638b87.